The present invention is directed to phase change inks. More specifically, the present invention is directed to hot melt or phase change inks containing specific colorant compounds. One embodiment of the present invention is directed to a phase change ink carrier and a colorant compound of the formula 
wherein M is either (1) a metal ion having a positive charge of +y wherein y is an integer which is at least 2, said metal ion being capable of forming a compound with at least two 
chromogen moieties, or (2) a metal-containing moiety capable of forming a compound with at least two 
chromogen moieties, z is an integer representing the number of 
chromogen moieties associated with the metal and is at least 2, R1, R2, R3, and R4 each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, wherein R1 and R2 can be joined together to form a ring, wherein R3 and R4 can be joined together to form a ring, and wherein R1, R2, R3, and R4 can each be joined to a phenyl ring in the central structure, a and b each, independently of the others, is an integer which is 0, 1, 2, or 3, c is an integer which is 0, 1, 2, 3, or 4, each R5, R6, and R7, independently of the others, is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, (iv) an alkylaryl group, (v) a halogen atom, (vi) an ester group, (vii) an amide group, (viii) a sulfone group, (ix) an amine group or ammonium group, (x) a nitrile group, (xi) a nitro group, (xii) a hydroxy group, (xiii) a cyano group, (xiv) a pyridine or pyridinium group, (xv) an ether group, (xvi) an aldehyde group, (xvii) a ketone group, (xviii) a carbonyl group, (xix) a thiocarbonyl group, (xx) a sulfate group, (xxi) a sulfide group, (xxii) a sulfoxide group, (xxiii) a phosphine or phosphonium group, (xxiv) a phosphate group, (xxv) a mercapto group, (xxvi) a nitroso group, (xxvii) an acyl group, (xxviii) an acid anhydride group, (xxix) an azide group, (xxx) an azo group, (xxxi) a cyanato group, (xxxii) an isocyanato group, (xxxiii) a thiocyanato group, (xxxiv) an isothiocyanato group, (xxxv) a urethane group, or (xxxvi) a urea group, wherein R5, R6, and R7 can each be joined to a phenyl ring in the central structure, 
R8, R9, and R10 each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, provided that the number of carbon atoms in R1+R2+R3+R4+R5+R6+R7+R8+R9+R10 is at least about 16, Qxe2x88x92 is a COOxe2x88x92 group or a SO3xe2x88x92 group, d is an integer which is 1, 2, 3, 4, or 5, A is an anion, and CA is either a hydrogen atom or a cation associated with all but one of the Qxe2x88x92 groups.
In general, phase change inks (sometimes referred to as xe2x80x9chot melt inksxe2x80x9d) are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet +operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.
Phase change inks for color printing typically comprise a phase change ink carrier composition which is combined with a phase change ink compatible colorant. In a specific embodiment, a series of colored phase change inks can be formed by combining ink carrier compositions with compatible subtractive primary colorants. The subtractive primary colored phase change inks can comprise four component dyes, namely, cyan, magenta, yellow and black, although the inks are not limited to these four colors. These subtractive primary colored inks can be formed by using a single dye or a mixture of dyes. For example, magenta can be obtained by using a mixture of Solvent Red Dyes or a composite black can be obtained by mixing several dyes. U.S. Pat. No. 4,889,560, U.S. Pat. No. 4,889,761, and U.S. Pat. No. 5,372,852, the disclosures of each of which are totally incorporated herein by reference, teach that the subtractive primary colorants employed can comprise dyes from the classes of Color Index. (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, and Basic Dyes. The colorants can also include pigments, as disclosed in, for example, U.S. Pat. No. 5,221,335, the disclosure of which is totally incorporated herein by reference. U.S. Pat. No. 5,621,022, the disclosure of which is totally incorporated herein by reference, discloses the use of a specific class of polymeric dyes in phase change ink compositions.
Phase change inks have also been used for applications such as postal marking, industrial marking, and labelling.
Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.
Compositions suitable for use as phase change ink carrier compositions are known. Some representative examples of references disclosing such materials include U.S. Pat. No. 3,653,932, U.S. Pat. No. 4,390,369, U.S. Pat. No. 4,484,948, U.S. Pat. No. 4,684,956, U.S. Pat. No. 4,851,045, U.S. Pat. No. 4,889,560, U.S. Pat. No. 5,006,170, U.S. Pat. No. 5,151,120, U.S. Pat. No. 5,372,852, U.S. Pat. No. 5,496,879, European Patent Publication 0187352, European Patent Publication 0206286, German Patent Publication DE 4205636AL, German Patent Publication DE 4205713AL, and PCT Patent Application WO 94/04619, the disclosures of each of which are totally incorporated herein by reference. Suitable carrier materials can include paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, fatty acids and other waxy materials, fatty amide containing materials, sulfonamide materials, resinous materials made from different natural sources (tall oil rosins and rosin esters, for example), and many synthetic resins, oligomers, polymers, and copolymers.
British Patent Publication GB 2 311 075 (Gregory et al.), the disclosure of which is totally incorporated herein by reference, discloses a compound of the formula 
wherein X1 is an ester group or an amide group (such as of a carboxylic or sulfonic acid) or a fatty amine salt of a sulfonic acid, each X2 independently is a substituent, m has a value of from 0 to 2, Y1 and Y2 are each independently H, alkyl, or halo, each Z independently is an ester or amide group, and Axe2x88x92 is on anion. The compound is useful as a colorant for toners, D2T2 printing, plastics, polyesters, nylons, and inks, especially ink jet or hot melt inks.
xe2x80x9cRhodamine Dyes and Related Compounds. XV. Rhodamine Dyes with Hydroaromatic and Polymethylene Radicals,xe2x80x9d I. S. Ioffe et al., Zh. Organ. Khim. (1965), 1(3), 584-6, the disclosure of which is totally incorporated herein by reference, discloses a process wherein heating dichlorofluoran with ZnCl2xe2x80x94ZnO and the appropriate amine for 3 hours at 220xc2x0 followed by treatment with aqueous HCl gave N,Nxe2x80x2-dicyclohexylrhodamine-HCl, m. 180-5xc2x0, N,Nxe2x80x2-di(tetramethylene)rhodamine-HCl, decompd. 240xc2x0, N,Nxe2x80x2-di(pentamethylene)rhodamine-HCl, m. 205-10xc2x0, N,Nxe2x80x2-di(hexamethylene)rhodamine-HCl, decompd. 175xc2x0. These dyes gave yellow or orange fluorescence and their spectra were given.
xe2x80x9cRhodamine Dyes and Related Compounds. XI. Aryl- and Alkylrhodamines Containing Carboxyl Groups,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1964), 34(6), 2041-4, the disclosure of which is totally incorporated herein by reference, discloses a process wherein heating aminobenzoic acids with 3,6-dichlorofluoran in the presence of ZnCl2 for 6 hours at 24-50xc2x0 gave after an aqueous treatment: N,Nxe2x80x2-bis(o-carboxyphenyl)rhodamine-HCl; m-isomer-HCl; and p-isomer-HCl. A similar reaction with HCl salts of glycine, xcex1-alanine, or xcex2-alanine gave: N,Nxe2x80x2-bis(carboxymethyl)rhodamine-HCl; N,Nxe2x80x2-bis(xcex1-carboxyethyl)rhodamine-HCl; and N,Nxe2x80x2-bis(xcex2-carboxyethyl)rhodamine-HCl, The latter group showed yellow-green fluorescence, lacking in the aryl derivatives. Spectra of the products are shown.
xe2x80x9cRhodamine Dyes and Related Compounds. X. Fluorescence of Solutions of Alkyl- and Arylalkylrhodamines,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1964), 34(6), 2039-41, the disclosure of which is totally incorporated herein by reference, discloses fluorescence spectra for the following rhodamines: N,Nxe2x80x2-diethyl: N,Nxe2x80x2-dibenzyl; N,Nxe2x80x2-bis(xcex2-phenylethyl); N,Nxe2x80x2-bis(xcex2-phenylisopropyl). In symmetrical substituted rhodamines, the entry of an alkyl or arylalkyl group into both amino residues resulted in the displacement of fluorescence max. toward longer wavelengths, a similar displacement of absorption and an increase in the quantum yield of fluorescence. In unsymmetrical derivatives, an aryl group entering one of the amino groups shifted the spectra to a greater degree in the same direction and sharply reduced the quantum yield of fluorescence.
Rhodamine Dyes and Related Compounds. IX. Rhodamine B Sulfonic Acids and their Derivatives,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1964), 34(2), 640-44, the disclosure of which is totally incorporated herein by reference, discloses that heating m-Et2NC6H4OH and K xcex2-sulfophthalate at 150xc2x0 while concentrated H2SO4 was being added gave after 3 hours at 150-70xc2x0, followed by heating with H2O 15 min., a residue of crude sulforhodamine, purified by solution in hot aqueous Na2CO3 and precipitation with AcOH. The mixed isomeric rhodamine sulfonic acids refluxed 3 hours with 30% AcOH, clarified, and cooled gave a first isomer with Rf 0.74 on paper in aqueous solution (pH 9) while the residue was the other isomer with Rf 0.98. The first isomer and PCl5 gave the sulfonyl chloride, isolated as HCl salt, red solid (from CHCl3-ligroine), which with NH3 in CHCl3 gave the sulfonamide, a violet powder. The two isomers and Rhodamine B had similar spectral characteristics. The two isomers probably contain the SO3H group in the 4- and 5-positions of the Ph ring of Rhodamine B. Their absorption and fluorescence spectra are shown. Their solutions in CHCl3 gave stronger fluorescence than those in Me2CO.
xe2x80x9cRhodamine Dyes and Related Compounds. VIII. Amides of Sulforhodamine B Containing xcex2-Hydroxyethyl and xcex2-Chloroethyl Groups,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1963), 33(12), 3943-6, the disclosure of which is totally incorporated herein by reference, discloses that sulforhodamine B chloride heated 10-12 hours with HOCH2CH2NH2 at 170-80xc2x0, then triturated with saturated NaCl gave, after solution in CHCl3 and precipitation with petroleum ether, 80% red sulforhodamine B N(xcex2-hydroxyethyl )amide; similar reaction with HN(CH2CH2OH)2 gave 70% N,N-bis(xcex2-hydroxyethyl)amide, a bright red wax. These treated with SOCl2 in CHCl3 gave, respectively, N-(xcex2-chloroethyl)amide, a brown powder, and N,N-bis(xcex2-chloroethyl)amide, a violet powder. Absorption spectra of the amides are shown. The (hydroxyethyl)amides displayed strong orange fluorescence in solution.
xe2x80x9cRhodamine Dyes and Related Compounds. VII. (xcex2-Phenylethyl)rhodamines,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1963), 33(4), 1089-92, the disclosure of which is totally incorporated herein by reference, discloses a process wherein heating dichlorofluoran with PhCH2CH2NH2 or PhCH2CH(Me)NH2 in the presence of ZnO and ZnCl2 for 5-6 hours at 220xc2x0 gave, after heating for 2 hours with aqueous HCl, 96-8% crude products which, after crystallization from alc. HCl, gave red, powdery N,Nxe2x80x2-bis(xcex2-phenylethyl)rhodamine-HCl, m. 172-5xc2x0, or N,Nxe2x80x2-bis(xcex1-methyl-xcex2-phenylethyl)rhodamine-HCl, m. 175-8xc2x0; N-phenyl-Nxe2x80x2-(xcex2-phenylethyl)rhodamine-HCl, m. 162-6xc2x0, was prepared from PhCH2CH2NH2 and 3xe2x80x2-chloro-6xe2x80x2-anilinofluoran under the above conditions. Treated with alc. NaOH and quenched in H2O, these hydrochlorides gave the free bases of the dyes as brown-red solids, which tended to form colloids in aqueous medium. The free bases m. 123-5xc2x0, decompd. 120xc2x0, and m. 164-8xc2x0, respectively. The ultraviolet and visible spectra of the dyes were similar to the spectra of dibenzylrhodamine, but had deeper color; strong fluorescence was shown by these dyes. The spectrum of the bis(xcex2-phenylethyl)rhodamine was almost identical with that of diethylrhodamine.
xe2x80x9cRhodamine Dyes and Related Compounds. VI. Chloride and Amides of Sulforhodamine B.xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1962), 32, 1489-92, the disclosure of which is totally incorporated herein by reference, discloses that sulforhodamine B (5 g, dried at 125xc2x0) and 3 g. PCl5 heated in 50 milliliters CHCl3 for 4 hours, then extd. with cold H2O to remove excess PCl6, gave, after concentration of the dried organic layer and treatment of the residue with much cold petroleum ether, the dark red p-sulfonyl chloride, C27H29O6N2S2Cl, which slowly forms the original compound on contact with H2O. With NH3 in CHCl3 it gave the corresponding p-sulfonamide, 81%, red-violet powder, sol. in EtOH or AcOH; similarly was prepared the p-sulfonanilide, brown-violet solid. These have absorption spectra similar to the original compound but with less intense absorption. The p-sulfonyl chloride has a more intense absorption than the amides.
xe2x80x9cRhodamine Dyes and Related Compounds. V. xcex1-Pyridylrhodamine,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1962), 32, 1485-9, the disclosure of which is totally incorporated herein by reference, discloses a process wherein heating 3,6-dichlorofluorane with 2-aminopyridine in the presence of ZnCl2 for 3 hours at 160-80xc2x0 gave, after extraction with hot H2O and EtOH and crystallization of the residue from aqueous Me2CO, 3-chloro-6-xcex1-pyridylaminofluorane-HCl, m. 280-2xc2x0; free base, m. 185-7xc2x0. This heated with 2-aminopyridine and ZnCl2 at 250-60xc2x0 for 6 hours, then precipitated from hot EtOHxe2x80x94HCl with H2O, gave red N,Nxe2x80x2-bis(xcex1-pyridyl)rhodamine-HCl, m. 238-40xc2x0, also formed directly from dichlorofluorane and excess aminopyridine at 250-60xc2x0. Similarly, 3-chloro-6-anilino-fluorane gave red-violet N-phenyl-Nxe2x80x2-xcex1-pyridylrhodamine-HCl, m. 225-30xc2x0. All these were converted to, N,Nxe2x80x2-diphenylrhodamine by heating with PhNH2 and ZnCl2 for 3 hours at 180-200xc2x0. The absorption spectra of the products are shown; dipyridylrhodamine has a more intense color than other members of the group.
xe2x80x9cRhodamine Dyes and Related Compounds. IV. Aryl- and Benzylrhodamines,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1962), 32, 1480-5, the disclosure of which is totally incorporated herein by reference, discloses a process wherein heating fluorescein chloride with ArNH2 in the presence of ZnCl2xe2x80x94ZnO for 4 to 5 hours at 210-20xc2x0 gave, after leaching with hot dil. HCl, soln. of the residue in hot PhNH2, and pptn. with dil. HCl, the following N,Nxe2x80x2-diarylrhodamines which were isolated as HCl salts: Ph, m. 255-60xc2x0; o-meC6H4, m. 205-10xc2x0; m-meC6H4, m. 195xc2x0200xc2x0; p-meC6H4, m. 255-60xc2x0. PhCH2NH2 similarly gave N,Nxe2x80x2-dibenzylrhodamine, m. 160-5xc2x0; HCl salt decomp. 160-5xc2x0; di-HCl salt decomp. 210xc2x0. PhCH2NH2 and 3-chloro-6-anilinofluorane gave 90-5% N-phenyl-Nxe2x80x2-benzylrhodamine isolated as the HCl salt, m. 200-10xc2x0. The absorption spectra of these rhodamines are shown. Dibenzylrhodamine fluoresces strongly in solution, while the phenyl benzyl analog has a weak fluorescence. The benzyl groups cause a bathochromic shift of the absorption band in the substituted rhodamines; the diarylrhodamines form blue-violet solutions unlike the orange-yellow produced by unsubstituted rhodamine. The di-HCl salt of dibenzylrhodamine loses one HCl in soln. as shown by behavior in EtOH.
xe2x80x9cRhodamine Dyes and Related Compounds. III. Reaction of m-aminophenol With Phthalic Anhydride in Hot Sulfuric Acid,xe2x80x9d I. S. Ioffe et al., Zh. Obsch. Khim. (1962), 32, 1477-80, the disclosure of which is totally incorporated herein by reference, discloses that heating 25 g. of m-H2NC6H4OH with 20 g. o-C6H4(CO)2O in 100 milliliters concentrated H2SO4 at 160-200xc2x0 for 2-8 hours was used to examine the effects of conditions of condensation on the reaction products. Rhodamine formation began at 170xc2x0 and reached a max. (20%) in 2 hours at 190xc2x0. Rhodol was a constant byproduct as a result of partial deamination of rhodamine. The deamination is promoted by longer reaction time and higher temperatures. These factors also promoted the formation of a dark, amorphous material. o-Hydroxysulfanilic acid was formed in the reaction in up to 32% yield at 160xc2x0 in 2 hours; more drastic conditions lowered its yield rapidly Prior to the appearance of substantial amounts of rhodamine in the mixture, sulfonation of m-H2NC6H4OH takes place, and the resulting compound appears to be the intermediate which reacts, with this compound forming rhodamine by displacement of the sulfonic acid group. This was confirmed by reaction of o-C6H4(CO)2O with o-hydroxysulfanilic acid under the conditions shown above. m-Aminosalicylic acid also yields the same products in a mixture similar to that formed by m-H2NC6H4OH.
xe2x80x9cRhodamine Dyes and Related Compounds. XVIII. N,Nxe2x80x2-Dialkylrhodamines with Long Chain Hydrocarbon Radicals,xe2x80x9d I. S. Ioffe et al., Zh. Organ. Khim. (1970), 6(2), 369-71, the disclosure of which is totally incorporated herein by reference, discloses a process wherein the condensation of I (X=Cl) with RNH2 (R=C6H13, C8H17, C16H33, or C18H37) gave the title dyes (I, X=NHR) (II). The presence of alkyl groups in II did not change their color in comparison with II (R=H); all II absorbed strongly at 523-6 nm. However, long alkyl chains altered the hydrophobic properties of II as shown by the change of their partition coefficients in oil-alc. or kerosine-alc. systems with the length of R chain.
xe2x80x9cRhodamine Dyes and Related Compounds. XIX. Mutual Transformations of Colorless and Colored Forms of N,Nxe2x80x2-Substituted Rhodamine,xe2x80x9d I. S. Ioffe et al., Zh. Organ. Khim. (1972), 8(8), 1726-9, the disclosure of which is totally incorporated herein by reference, discloses that substituted rhodamines give colored solutions in polar and colorless solutions in nonpolar solvents. The solvent polarity at which the colorless lactone form is converted to the quinoid, internal salt form depends on the number and structure of alkyl, aryl, or H substituents. Absorption spectra of N,Nxe2x80x2-diethylrhodamine in water-dioxane mixtures show how the light absorption increases when the solvent polarity (i.e., water amount in the mixture) is increased.
xe2x80x9cSynthesis of N-Substituted Flaveosines, Acridine Analogs of Rhodamine Dyes,xe2x80x9d I. S. Ioffe et al., Zh. Org. Khim. (1966), 2(9), 1721, the disclosure of which is totally incorporated herein by reference, discloses that o-(3,6-chloro-9-acridinyl)benzoic acid heated with BuNH2 or Bu2NH readily gave the hydrochlorides.
xe2x80x9cRhodamine Dyes and Related Compounds. XVII. Acridine Analogs of Rhodamine and Fluorescein,xe2x80x9d I. S. Ioffe et al., Zh. Organ. Khim. (1966), 2(5), 927-31, the disclosure of which is totally incorporated herein by reference, discloses absorption spectra for flaveosin, fluorescein, azafluorescein, their Et esters and diacetyl derivatives. Replacement of the xanthene structure by the acridine group changed the spectra of such dyes. Azafluorescein heated with PCl5 at 95-100xc2x0 gave o-(3,6-dichloro-9-acridinyl)-benzoic acid, decomp.  greater than 300xc2x0; its uv spectrum was similar to that of unsubstituted acridinylbenzoic acid. One of the flaveosin compounds heated with 25% H2SO4 in a sealed tube 10 hours at 200-20xc2x0 gave azafluorescein, decomp.  greater than 380xc2x0; heated with EtOHxe2x80x94H2SO4 it gave one of the flaveosins, decomp.  greater than 300xc2x0 Ac2Oxe2x80x94H2SO4 gave in 1 hour one of the flaveosins, decomp. 206xc2x0. The compound formed by treatment of 3,6-dichlorofluorane with NH3 was prepared. Its uv spectrum is given.
xe2x80x9cNew Lipophilic Rhodamines and Their Application to Optical Potassium Sensing,xe2x80x9d T. Werner et al., Journal of Fluorescence, Vol. 2, No. 3, pp. 93-98 (1992), the disclosure of which is totally incorporated herein by reference, discloses the synthesis of new lipophilic fluorescent rhodamines directly from 3,6-dichlorofluoresceins and the respective long-chain amines with excellent solubility in lipids and lipophilic membranes. Spectrophotometric and luminescent properties of the dyes are reported and discussed with respect to their application in new optical ion sensors. One rhodamine was applied in a poly(vinyl chloride)-based sensor membrane for continuous and sensitive optical determination of potassium ion, using valinomycin as the neutral ion carrier.
U.S. Pat. No. 1,991,482 (Allemann), the disclosure of which is totally incorporated herein by reference, discloses a process of producing rhodamine dyes which comprises condensing a halogenated primary amine of the benzene series with fluorescein dichloride and sulfonating the condensed product.
U.S. Pat. No. 5,847,162 (Lee et al.), the disclosure of which is totally incorporated herein by reference, discloses a class of 4,7-dichlororhodamine compounds useful as fluorescent dyes having the structure 
wherein R1-R6 are hydrogen, fluorine, chlorine, lower alkyl lower alkene, lower alkyne, sultanate, sulfone, amino, amido, nitrile, lower alkoxy, lining group, or combinations hereof or, when taken together, R1 and R6 is benzo, or, when taken together, R4 and R5 is benzo; Y1-Y4 are hydrogen or lower alkyl or, when taken together, Y1 and R2 is propano and Y2 and R1 is propano, or, when taken together, Y3 and R3 is propano and Y4 and R4 is propano; and X1-X3 taken separately are selected from the group consisting of hydrogen, chlorine, fluorine, lower alkyl carboxylate, sulfonic acid, xe2x80x94CH20H, and linking group. In another aspect, the invention includes reagents labeled with the 4,7-dichlororhodamine dye compounds, including deoxynucleotides, dideoxynucleotides, and polynucleotides. In an additional aspect, the invention includes methods utilizing such dye compounds and reagents including dideoxy polynucleotide sequencing and fragment analysis methods.
U.S. Pat. No. 4,935,059 (Mayer et al.), the disclosure of which is totally incorporated herein by reference, discloses basic rhodamine dyes suitable for use in recording fluids for the ink jet process and for coloring paper stock having the formula 
where L is C2-C10-alkylene, R1, R2, and R3 are each independently of the others hydrogen, substituted or unsubstituted C1-C10-alkyl or C5-C7-cycloalkyl or R1 and R2 together with the nitrogen atom linking them together are a hetero cyclic radical, Anxe2x88x92 is one equivalent of an anion and m and n are each independently of the other 0 or 1.
U.S. Pat. No. 4,647,675 (Mayer et al.), the disclosure of which is totally incorporated herein by reference, discloses compounds of the general formula 
where Axe2x88x92 is an anion, R is hydrogen or unsubstituted or substituted alkyl or cycloalkyl, R1 and R2 independently of one another are each hydrogen or unsubstituted or substituted alkyl or cycloalkyl, or one of the radicals may furthermore be aryl, or R1 and R2, together with the nitrogen atom, form a saturated heterocyclic structure, the radicals R3 independently of one another are each hydrogen or C1-C4-alkyl, R4 and R5 independently of one another are each unsubstituted or substituted alkyl or cycloalkyl, or one of the radicals may furthermore be hydrogen, aryl or hetaryl, R4 and R5, together with the nitrogen atom, form a saturated heterocyclic structure, n is 1, 2 or 3, X is hydrogen, chlorine, bromine, C1-C4-alkyl, C1-C4-alkoxy or nitro and Y is hydrogen or chlorine, are particularly useful for dyeing paper stocks.
U.S. Pat. No. 1,981,515 (Kyrides), the disclosure of which is totally incorporated herein by reference, discloses intermediates for rhodamine dyestuffs.
U.S. Pat. No. 1,981,516 (Kyrides), the disclosure of which is totally incorporated herein by reference, discloses intermediates for secondary alkylated rhodamine dyes.
British Patent Publication GB 421 737, the disclosure of which is totally incorporated herein by reference, discloses dyes of the rhodamine series which are prepared by condensing naphthalene-2:3-dicarboxylic acid with a m-aminophenol in which the nitrogen group is substituted by one or two alkyl groups, the products, if desired, being sulphonated. The unsulphonated products may be used as lake colouring matters whilst the sulphonated dyes are acid wool dyes. In examples, (1) naphthalene-2:3-dicarboxylic acid is condensed with diethyl-m-aminophenol in the presence of zinc chloride giving a product which dyes tannin-mordanted cotton in the same shade as Rhodamine B and a sulphonated product which dyes wool bluish-red shades; (2) monoethyl-m-aminophenol is used instead of the diethyl-m-aminophenol in example (1); yielding a dye, which when sulphonated dyes wool red-orange shades; (3) 2-ethylamino-p-cresol replaces the diethyl-m-aminophenol in example (1), yielding a dye dyeing and printing tannin-mordanted cotton in shades similar to Rhodamine 69BS and when sulphonated dyeing wool red.
Japanese Patent Publication JP 61221265, the disclosure of which is totally incorporated herein by reference, discloses rhodamine compounds of formula I 
wherein R1, R3 are each lower alkyl; R2 is lower alkyl, 10C or higher long-chain alkyl R4 is 10C or higher long-chain alkyl; Xxe2x88x92 is on anion, or squarylium compounds of formula II 
wherein R2 is 10C or higher long-chain alkyl. Example: 3,6-(N,Nxe2x80x2-diethyl-N,Nxe2x80x2-dioctadecyl)diamino-9-(2-carboxyphenyl)xanthilium perchlorate. Use: materials for molecular electronics, which are suitable for use as materials for photoelectric converter, optical memory, etc. Preparation: 2-(4-N,Nxe2x80x2-diethylamino-2-hydroxybenzoyl)-benzoic acid, which is a condensate between N-ethyl-N-octadecyl-m-hydroxyaniline and phthalic anhydride, is reacted with N-ethyl-N-octadecyl-m-hydroxyaniline to obtain the compound of formula I. 3-HOC6H4N(Et)(CH2)17Me and phthalic anhydride were heated at 150xc2x0 for 4 hours, treated with aqueous NH3, and the amorphous intermediate mixed with aqueous HClO4 forming a compound of formula I (R=R2=Et; R1=R3=C18H37; X=ClO4), having xcexmax (MeOH) 550 nm.
U.S. Pat. No. 5,084,099 (Jaeger et al.), the disclosure of which is totally incorporated herein by reference, discloses modified phase change ink compatible colorants which comprise a phase change ink soluble complex of (a) a tertiary alkyl primary amine and (b) dye chromophores, i.e., materials that absorb light in the visible wavelength region to produce color having at least one pendant acid functional group in the free acid form (not the salt of .that acid). These modified colorants are extremely useful in producing phase change inks when combined with a phase change ink carrier, even though the unmodified dye chromophores have limited solubility in the phase change ink carrier. Thin films of uniform thickness of the subject phase change ink compositions which employ the modified phase change ink colorants exhibit a high degree of lightness and chroma. The primary amine-dye chromophore complexes are soluble in the phase change ink carrier and exhibit excellent thermal stability.
U.S. Pat. No. 5,507,864 (Jaeger et al.), the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition that includes a combination of different dye types such as an anthraquinone dye and a xanthene dye, which is most preferably a rhodamine dye. While each dye type is insufficiently soluble with respect to favored carrier compositions to preserve color saturation in reduced ink quantity prints, the dye type combination permits increased dye loading and maintains print quality. In a preferred embodiment of the invention, a favored carrier composition is adjusted to promote the colored form of a preferred rhodamine dye (C.I. Solvent Red 49) and mixed with a preferred anthraquinone dye (C.I. Solvent Red 172) whose concentration is kept below a critical level to prevent post printed blooming. The resulting preferred phase change ink compositions provide a magenta phase change ink with enhanced light fastness and color saturation, as well as good compatibility with preferred existing subtractive primary color phase change inks.
U.S. Pat. No. 5,621,022 (Jaeger et al.), the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition wherein the ink composition utilizes polymeric dyes in combination with a selected phase change ink carrier composition.
U.S. Pat. No. 5,747,554 (Sacripante et al.), the disclosure of which is totally incorporated herein by reference, discloses an ink composition comprising a polyesterified-dye (I) or polyurethane-dye (II) with a viscosity of from about 3 centipoise to about 20 centipoise at a temperature of from about 125xc2x0 C. to about 165xc2x0 C. and represented by the formulas 
wherein A is an organic chromophore, Y is an oxyalkylene or poly(oxyalkylene), R is an arylene or alkylene, n represents the number of repeating segments, and is an integer of from about 2 to about 50, and p represents the number of chains per chromophore and is an integer of from about 1 to about 6.
U.S. Pat. No. 5,902,841 (Jaeger et al.), the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition wherein the ink composition utilizes colorant in combination with a selected phase change ink carrier composition containing at least one hydroxy-functional fatty amide compound.
European Patent Publication 0 565 798 (Shustack), the disclosure of which is totally incorporated herein by reference, discloses ultraviolet radiation-curable primary and secondary coating compositions for optical fibers. The primary coatings comprise a hydrocarbon polyol-based reactively terminated aliphatic urethane oligomer; a hydrocarbon monomer terminated with at least one end group capable of reacting with the terminus of the oligomer; and an optional photoinitiator. The secondary coatings comprise a polyester and/or polyether-based aliphatic urethane reactively terminated oligomer; a hydrocarbonaceous viscosity-adjusting component capable of reacting with the reactive terminus of (I); and an optional photoinitiator. Also disclosed are optical fibers coated with the secondary coating alone or with the primary and secondary coatings of the invention.
While known compositions and processes are suitable for their intended purposes, a need remains for new magenta colorant compositions. In addition, a need remains for magenta colorant compositions particularly suitable for use in phase change inks. Further, a need remains for magenta colorants with desirable thermal stability. Additionally, a need remains for magenta colorants that exhibit minimal undesirable discoloration when exposed to elevated temperatures. There is also a need for magenta colorants that exhibit a desirable brilliance. In addition, there is a need for magenta colorants that exhibit a desirable hue. Further, there is a need for magenta colorants that are of desirable chroma. Additionally, there is a need for magenta colorants that have desirably high lightfastness characteristics. A need also remains for magenta colorants that have a desirably pleasing color. In addition, a need remains for magenta colorants that exhibit desirable solubility characteristics in phase change ink carrier compositions. Further, a need remains for magenta colorants that enable phase change inks to be jetted at temperatures of over 135xc2x0 C. while maintaining thermal stability. Additionally, a need remains for magenta colorants that enable phase change inks that generate images with low pile height. There is also a need for magenta colorants that enable phase change inks that generate images that approach lithographic thin image quality. In addition, there is a need for magenta colorants that exhibit oxidative stability. Further, there is a need for magenta colorants that do not precipitate, from phase change ink carriers. Additionally, there is a need for magenta colorants that do not, when included in phase change inks, diffuse into adjacently printed inks of different colors. A need also remains for magenta colorants that do not leach from media such as phase change ink carriers into tape adhesives, paper, or the like. In addition, a need remains for magenta colorants that, when incorporated into phase change inks, do not lead to clogging of a phase change ink jet printhead. Further, there is a need for magenta colorants that enable phase change inks that generate images with sharp edges that remain sharp over time. Additionally, there is a need for magenta colorants that enable phase change inks that generate images which retain their high image quality in warm climates. Further, there is a need for magenta colorants that enable phase change inks that generate images of desirably high optical density. Additionally, there is a need for magenta colorants that, because of their good solubility in phase change ink carriers, enable the generation of images of low pile height without the loss of desirably high optical density. A need also remains for magenta colorants that enable cost-effective inks. In addition, a need remains for magenta colorants that are compounds having metal compounds associated with chromogens, wherein the thermal stability of the metal compound colorants exceeds that of the chromogens unassociated with a metal.
The present invention is directed to a phase change ink composition comprising a phase change ink carrier and a colorant compound of the formula 
wherein M is either (1) a metal ion having a positive charge of +y wherein y is an integer which is at least 2, said metal ion being capable of forming a compound with at least two 
chromogen moieties, or (2) a metal-containing moiety capable of forming a compound with at least two 
chromogen moieties, z is an integer representing the number of 
chromogen moieties associated with the metal and is at least 2, R1, R2, R3, and R4 each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, wherein R1 and R2 can be joined together to form a ring, wherein R3 and R4 can be joined together to form a ring, and wherein R1, R2, R3, and R4 can each be joined to a phenyl ring in the central structure, a and b each, independently of the others, is an integer which is 0, 1, 2, or 3, c is an integer which is 0, 1, 2, 3, or 4, each R5, R6, and R7, independently of the others, is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, (iv), an alkylaryl group, (v) a halogen atom, (vi) an ester group, (vii) an amide group, (viii) a sulfone group, (ix) an amine group or ammonium group, (x) a nitrile group, (xi) a nitro group, (xii) a hydroxy group, (xiii) a cyano group, (xiv) a pyridine or pyridinium group, (xv) an ether group, (xvi) an aldehyde group, (xvii) a ketone group, (xviii) a carbonyl group, (xix) a thiocarbonyl group, (xx) a sulfate group, (xxi) a sulfide group, (xxii) a sulfoxide group, (xxiii) a phosphine or phosphonium group, (xxiv) a phosphate group, (xxv) a mercapto group, (xxvi) a nitroso group, (xxvii) an acyl group, (xxviii) an acid anhydride group, (xxix) an azide group, (xxx) an ozo group, (xxxi) a cyanato group, (xxxii) an isocyanato group, (xxxiii) a thiocyanato group, (xxxiv) an isothiocyanato group, (xxxv) a urethane group, or (xxxvi) a urea group, wherein R5, R6, and R7 can each be joined to a phenyl ring in the central structure, 
R8, R9, and R10 each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, provided that the number of carbon atoms in R1+R2+R3+R4+R5+R6+R7+R8+R9+R10 is at least about 16, Qxe2x88x92 is a COOxe2x88x92 group or a SO3xe2x88x92 group, d is an integer which is 1, 2, 3, 4, or 5, A is an anion, and CA is either a hydrogen atom or a cation associated with all but one of the Qxe2x88x92 groups.